DE9102348U1 - Load measuring and display device for lifting equipment - Google Patents

Description

Description

&bgr; Load measuring and display device for lifting equipment

&bgr; The invention relates to a device which can be fixed in the lifting line of a hoist.

9 Load measuring and display device for measuring the load on the lifting line

10 effective trailer load. Such devices consist essentially

11 consists of a measuring element, a measuring and evaluation electronics and a

12 Measured value display. As a rule, the trailer load acts directly on the measuring element and causes a change in the state of the measuring element. This change in state is recorded by the measuring and evaluation electronics as an input signal.

is and processed into an output signal. The output signal of the measuring

ie and evaluation electronics in turn forms the input signal for the

&igr;? Measured value display. The measured value display ultimately shows the

The trailer load acting on the lifting line.

20 This makes it easy to see whether the maximum permissible trailer load

21 is exceeded. Furthermore, with the help of such a device, the

22 actual trailer load close to the limit of the maximum permissible

23 trailer load can be increased. It is therefore possible to increase the trailer load in

24 towards the permissible maximum load. Such known

25 Load measuring and display devices are often attached to load cranes 2&bgr;, which is why they are also called "crane scales".

27 Conventional "crane scales" have a measuring element, the measuring and

2&bgr; evaluation electronics and a housing that encloses the measured value display.

29 This housing protects the components mentioned against external influences,

µgr; especially external temperature and humidity influences as well as

si mechanical impact stresses.

33 If, in connection with such a device, a

34 lifting line, this lifting line can be a chain, wire rope, textile

35 lifting strap, round sling or as a normal rope. The adaptation of the device in the lifting line is usually carried out in the following way: The

37 adapted device divides the lifting line into two parts. The "upper",

The hoist-side part of the rope hangs between the lifting arm of the hoist and

4 April 1991

&igr; the top of the device and the "lower", load-side part of the strand hangs

&zgr; between the bottom of the device and the trailer load itself. Of course

3 it is also possible to install the device directly between the lifting line and the

4 Towing capacity to be adapted by yourself.

&bgr; The object of the invention is to provide a load measuring and display device in

7 to simplify their structure and to be advantageous in terms of manufacturing

βgr; This task is achieved by the combination of features of the

9 Claim 1 resolved.

11 The housing of the device essentially faces in the direction of stroke of the

12 lifting line running side walls and essentially transverse to the

13 cover elements extending in the stroke direction. One of the cover elements is designed in such a way that it simultaneously accommodates the measuring element. This integrated design of the cover element is as a housing component on the one hand and as

The measuring element on the other hand allows a short design of the device in

&igr;? Stroke direction. The height of the device in stroke direction determines the

The maximum possible lifting height of the trailer load by the hoist. With other

19 words: the maximum possible lifting height of the trailer load is reduced by

20 the height of the device. Due to the short design and

21 The low height of the device means that the maximum possible

22 Lifting height for the trailer load on the hoist is almost retained.

24 The dual function of the cover element as a measuring sensor and

2s simultaneously as a housing component reduces on the one hand manufacturing

26 favourably reduces the number of components and also reduces the weight of the

27 device. This reduction in the weight of the device enables

28 again ensures a high degree of utilisation of the maximum permissible trailer load.

29 The weight of the device is therefore negligible compared to the maximum permissible weight of the trailer load.

32 In addition, the low weight of the device increases its

33 Safety and ease of use. The operator can

34 Lift the device slightly with one hand and hold it with one hand while

35 connects the device to the lifting line. In the event of the device falling, the device's light weight also reduces the potential risk of injury.

4 April 1991

&igr; The trailer load adapted to the cover element causes an elastic

2 Deformation of the cover element. The cover element deforms

3 membrane-like for measuring the trailer load. Such a

4 technical membrane is in Brockhaus, Natural Sciences and Technology,

5 Volume 3, p. 243, Wiesbaden 1983, there 2). The resistance element, which is connected to the cover element by means of a carrier foil &bgr;, deforms

7 proportional to the elastic deformation of the cover element. This

β Proportional deformation of the resistance element in turn causes a

9 Change in its electrical resistance. This continuous

10 Change in the electrical resistance is used as input signal for the

11 measuring and evaluation electronics. The continuity of this

12 Change in inherent resistance enables the detection of very narrowly stepped and

13 thus very precise measurement values. Even a small elastic deformation of the

u Housing cover causes a change in the electrical resistance and

This means that the measuring and evaluation electronics respond particularly sensitively.

ie In particular, this enables the detection of very small changes in the

17 trailer load. The inventive design of the measuring element is therefore

te with a high weighing accuracy. The weighing accuracy varies by

ie about 0.1% for the versions of the device with a maximum

20 Towing capacity of two tonnes on the one hand and five tonnes on the other.

21 structurally simple design of the inventive load measuring and

22 display device does not therefore affect the weighing accuracy.

24 The load measurement via the change in the electrical

25 The inherent resistance provides an electrical input signal to the measuring and evaluation electronics and can be further processed into an electrical output signal for the measured value display. This output signal from the measuring and evaluation electronics simultaneously forms the input signal for the

29 Measured value display. This input signal is also suitable as an input signal

for a discrete, especially digital, measured value display.

32 The load measurement via the deformation of the cover element at

33 simultaneous deformation of the cover element in motion

34 connected measuring element, preferably a strain gauge,

35 also advantageously eliminates the need for moving parts.

These strain gauges are from Brockhaus, Natural Sciences and Technology,

37 1. Volume, p.238, Wiesbaden 1983 generally known and in E. Schrüfer,

see "Electrical Measurement Technology", p.217 ff., 2nd edition, Carl Hanser Verlag Munich

4 April 1991

&igr; Vienna, explained in detail. This lack of moving parts improves the

2 wear behaviour of the device considerably. Furthermore, the particularly rigid

3 Structure of the device compared to devices with relative

4 moving parts has the advantage that the rigid construction does not require

5 losses due to friction can occur. Such friction losses would lead to a &bgr; distortion of the measurement result. Due to the rigidity of the

7 individual parts to each other, the device continues to have a high dimensional stability

β. In contrast to load measuring and display devices with

9 moving parts, small moments occur in the device itself. This

10, in conjunction with the dimensional stability, increases the operational reliability of the

11 Device. A failure of the supporting function of the device in the lifting line is only

12 in the event of destruction of the entire device.

14 When designing the side walls according to claim 2, it is possible

Commercially available pipes are to be used to manufacture the hollow cylinder.

The pipes only need to be cut to the appropriate size

&igr;? The further development of the cylindrical side walls according to the

The design according to claims 3 to 5 as two-part hollow cylinders is particularly advantageous.

19 Here, an inner tube serves as a shield for the inner, measuring and

20 evaluation electronics. This inner tube is

21 an outer tube in such a way that between the outer wall of the

22 inner tube and the inner wall of the outer tube a cushion-like air jacket

23 is created. This air jacket shields the inner tube and thus the measuring and

24 Evaluation electronics in the form of insulation against external

25 temperature fluctuations. Such temperature fluctuations could in 2&bgr; extreme cases lead to measurement errors. This shielding against

27 Radiant heat also has the advantage that the distance between

2β Outer pipe inner wall and inner pipe outer wall Impact effects on the

29 The outer tube is supported by the outer tube in a crumple zone and not

thus affecting the inner tube and thus the measuring electronics. Due to the

31 favorable resistance bending moments of circular bodies increases the

32 cylindrical design of the side wall cross-section the dimensional stability of the

33 Device additionally.

35 Claims 6 to 9 teach the advantageous development of the cover elements

se in adaptation to the cylindrical design of the side walls. The

37 The cover element connected to the hoist-side partial strand forms the

the housing cover and the cover element facing away from the housing cover

4 April 1991

&igr; Case bottom. The case bottom also serves as a measuring element. The

2 The case back is a circular disc made of high-tempered steel

3. In the centre of this disc is a shaft coupling for

4 Can be adapted to accommodate a lifting device. At the same time, the

5 Housing base with the carrier film applied

β Strain gauge. The application of the strain gauge to the

7 Housing bottom is particularly advantageous because any possible

&bgr; Condensation or rainwater immediately drips off the bottom of the housing, which

&thgr; damage to the measuring element by such rain or

io Condensation is prevented.

12 The adaptation of the lifting gear via shaft couplings according to the teaching of

13 Claims 10 to 14 provide a fully cardanic suspension of the device

14 between the hoist-side part of the strand and the load-side part of the strand.

is This fully cardanic suspension allows the device for reading

ie the measured value display to any position. In addition, when

&igr;? fully cardanic suspension no transverse forces on the shaft couplings,

which could affect the operational safety of the device.

Due to this effective elimination of transverse forces, the device can consistently

20 must be designed to the longitudinal forces to be transmitted. In addition,

21 It is impossible for transverse forces to distort the measurement result of the device.

22 The design of the shaft couplings with three finger-like in the stroke direction

23 protruding joint projections allows the use of commercially available,

24 standardized lifting devices. Such lifting devices can be used as

25 load hooks, safety load hooks, shackles, suspension links or 2&bgr; round sling couplings.

28 The fixed bearing-like fixation of the inner tube in connection with the

29 The loose bearing-like fixing of the outer tube according to claims 15 to 18 ensures, on the one hand, the aforementioned thermal shielding of the cavity and the measuring electronics inside and, on the other hand, acts as an encapsulation of the

32 cavity against penetrating dirt, such as liquid, dust

33 etc. In particular, water or other conductive

34 Liquids can cause malfunctions in the measuring and display electronics.

35 Cohesion of housing cover and housing base and the

The two intermediate cylindrical tubes are like tie rods

37 Threaded bolts penetrating the housing cover into the space between the

between the tubes and placed in the housing base

4 April 1991

&igr; screwed in. Since these threaded bolts only have tensile forces, but no

2 Transverse forces can be transmitted using threaded bolts with a comparatively low

3 wall thickness can be used. As threaded bolts, screws with

4 of a small nominal size, which reduces the weight of the

5 device is further advantageously reduced.

7 Due to the tensioning effect of the screws acting as tie rods

βgr; on the one hand the dimensional stability of the device is increased and on the other hand the

9 Sealing effect of the fixed bearing-like inner tube is advantageously increased. The

10 floating bearing type mounting of the outer tube according to claim 18 with clearance between

11 the housing cover and the housing base allows an undisturbed

12 Deformation of the housing base and housing cover without affecting the measurement result ta.

is The fixation of the measuring electronics on the housing base connected

The stud bolt according to claim 19 is particularly suitable in connection with the

&igr;? Design of the housing base as a measuring element is advantageous.

The measuring element and the measuring and evaluation electronics work together advantageously

19. In particular, the signal paths from the measuring element to the measuring and

20 evaluation electronics short. Furthermore, the device can be used for repair purposes

21 can be easily opened, whereby the housing base with measuring element and measuring

22 and evaluation electronics stored resting on a work table, for example

23 and the housing cover and side panels can be easily lifted off

24. This can cause damage to the measuring element and the measuring and

25 evaluation electronics during such repairs.

27 The design of the display slot for the measured value display according to

28 Claims 20 and 21 allow a safe reading of the measured value display

29 even under difficult lighting conditions. The digital liquid crystal display enables, for example, a digit size of 25 mm to

si safe reading of the measured value from a distance of up to 10 m. The

32 Attachment of a protective cover according to claim 21 effectively prevents the

33 Damage to the liquid crystal display due to external influences, such as:

34 Impact stress and liquid exposure. Through the theory of

35 According to claims 20 and 21, the robustness and stability of the display shaft is adapted to the rest of the device.

4 April 1991

&igr; The design of the strain gauge according to claims 22 to 24

2 ensures the advantageous and permanent movement connection of

3 strain gauges and housing base. The arrangement of the

4 Strain gauge according to claims 23 and 24 is additionally a

5 continuous and using the entire housing base as a measuring element &bgr; load measurement is ensured. The wave-like load across the

7 Deformation spreading through the housing base under load is

β strain gauges can be measured safely and precisely in this way.

9, a strain gauge designed in this way comes with a relatively short

10 resistance element. This design combines the advantages of a short

11 resistance elements with the advantages of a large measuring area.

13 The invention is illustrated in the figures

U embodiment with further features essential to the invention

is described. Shown are:

&igr;? Fig. 1 an external view of the load measuring and display device in a side view looking towards the display shaft and

20 Fig. 2 is a sectional view of the device taken along the line H-II in Fig. 1.

22 The load measuring and control device which can be fixed in the lifting line of a hoist

The display device 1 in Fig. 1 comprises an outer tube 2, a

24 housing cover 3 and a housing base 4. The

25 Housing cover 3 is located in lifting direction 5 on the hoist side

26 front side 6 of the outer tube 2 and is designed as a circular, in the transverse direction 7

27 extending disc. The housing cover 3

2β opposite, on the load-side front side 8 of the outer tube 2

2&THgr; resting housing base 4 is also a transversely directed 7

circular disk extending in this way. On the cylindrical surface of the

31 outer tube 2, the indicator shaft 9 is welded on. In the indicator shaft 9,

32 the liquid crystal display 10 from the protruding metal frame 11

33. The metal frame 11 shields the liquid crystal display

34 against both external light influences and external stress

35 or exposure to liquids.

April 4, 1981

&igr; The housing cover 3 and the housing base 4 are in their centers

ζ according to the auxiliary line H-Il as flange-like fastening elements for the

3 hoist-side shaft coupling 12 and load-side shaft coupling 13

4. For connection to the not shown in the drawings

5 lifting line, the &bgr; suspension link 14 can be adapted in the lifting direction 5 to the shaft coupling 12 on the hoist side and to the shaft coupling 13 on the load side of the

7 Load hook 15 can be adapted as a stop element. To adapt the

β suspension link 14 and the load hook 15 to the shaft couplings 12,13

&thetas; are in the transverse direction 7, not shown in the drawings, the

io Shaft couplings 12,13 and bolts penetrating the lifting devices 14,15

ti inserted. The shaft coupling 12 on the hoist side has the three finger-like

12 in the stroke direction 5 protruding joint projections 16. The

13 The fastening side 17 of the suspension link 14 facing the shaft coupling 12 is U with the three complementary joint projections 16

is provided with fixing projections 16 ^1. The not shown in the drawings, in

The bolt running in the transverse direction 7 passes through the joint projections 16 and the

17 Fixing projections 16' along the auxiliary lines 18,18 ¹ .

19 Analogous to the hoist-side shaft coupling 12 and the suspension link 14,

20 the load-side shaft coupling 13 with the associated load hook 15

si. The shaft coupling 13 also has three joint projections 16,

22 to which the fixing projections 16' on the fastening side 17 of the

23 load hook 15 are complementary. The joint projections 16 on

24 of the shaft coupling 13 and the fixing projections 16 ¹ are

25 Auxiliary line 18 on the shaft coupling 13 and the auxiliary line 18 ¹ on the load hook 15 in

26 Transverse direction 7 penetrated.

2&bgr; The shaft couplings 12,13 form in combination with the suspension link 14

28 and the load hook 15 a fully cardanic suspension for the

so Load measuring and display device 1. The hoist side

si shaft coupling 12 is fixed to the housing cover 3 in such a way that

32 the display slot 9 with the liquid crystal display 10 always to the

33 can be rotated towards the viewer and thus aligned.

4 April 1991

&igr; From the sectional view according to Fig. 2, the rotatable bearing of the

2 hoist-side shaft coupling 12. The O-ring 19 is for

a Fixing of the shaft coupling 12 molded into the housing cover 3. The

4 Shaft coupling 12 is rotatable in the housing cover 3 via the axial bearing 20

5 stored.
&bgr;

7 In the stroke direction 5, the outer tube 2 runs essentially parallel to the

β also cylindrical inner tube 21. The outer tube 2 and the inner tube 21

&thetas; are arranged in the transverse direction 7 at a distance from each other such that they

io form the intermediate cavity 22 between them. The inner tube 21 encapsulates in

ti on its side facing away from the intermediate cavity 22 the

12 cavity 23.

U To brace the housing cover 3 and the housing base 4 against

is the inner tube 21 and the outer tube 2, several threaded bolts 24 are in the

The housing base 4 is screwed in. The threaded bolts 24 penetrate the

17 Housing cover 3 in through holes 25 and run in stroke direction 5

ie passing through the intermediate cavity 22 in the direction of the housing bottom 4.

19 The inner tube faces 26,26' are fixedly supported on the

20 housing base 4 or housing cover 3 and store the inner tube 21 in

21 its axial direction corresponding to the stroke direction 5. For the storage of the

22 inner tube 21 in its radial direction corresponding to the transverse direction 7

23 is on the housing cover 3 which in stroke direction 5 in the direction of the

24 Housing base 4 from the housing cover 3 protruding step-like

25 projection 27' and analogously on the housing base 4 in the stroke direction 5 in

26 towards the housing cover 3 protruding from the housing base 4

27 is formed with a shoulder-like projection 27. The outer tube 2 is, in contrast to the

28 Inner tube 21 is only supported on the projections 27,27* in its radial direction corresponding to the transverse direction 7. In its

so stroke direction 5 corresponding axial direction, the outer tube 2 is located according to

si the markings 28 with clearance on the front side of the housing base 4 and on the

32 Housing cover 3.

34 The circuit boards 29,29' positioned in the cavity 23 rest on the

35 Stud bolts 30. The stud bolts 30 are connected to the housing base 4 by means of the fastening screws 31. In the load-side bottom 32 of the

37 of the housing base 4, an annular strain gauge 33 is inserted.

se The case back 4 is made of highly tempered steel.

4 April 1991

&zgr; The mode of operation of the load measuring and display device 1 is as follows:

3 Under the weight of the shaft coupling 13 connected to the load side by means of the

4 load hook 15 attached trailer load deforms the highly tempered

5 steel existing housing base 4 in stroke direction 5 elastic. With this

&bgr; elastic deformation of the housing base 4 also deforms the

7 Strain gauge 33. Due to the deformation of the strain gauge 33

β changes the electrical resistance of the in the drawings not

&thgr; resistance element on the strain gauge 33. This

io electrical resistance of the resistance element in the

&kgr; Strain gauge 33 is connected to the printed circuit boards 29,29'

12 applied measuring and evaluation electronics via a

is Figure drawings not shown data line as input signal

µm. The measuring and

is evaluation electronics processes this input signal into an output signal

ie to the liquid crystal display 10. This serves as an input signal for the

17 Liquid crystal display 10 serving output signal of the measuring and

The evaluation electronics are connected via a not shown in the figure drawings

The data line is passed on to the liquid crystal display 10. For this purpose, a

20 the inner tube 21 and the outer tube 2 in the transverse direction 7 penetrating the

21 cavity 23 connecting the liquid crystal display 10

22 Cable passage channel 34. This measured value is based on the

23 Fixation 35 in the display slot 9 fixed liquid crystal display 10

24 can be read.

4. ααδαμ9θ1

List of reference symbols Load measurement and Marking (game Stud bolts 1 Display device from pipe 2) Outer tube 29.29' PCB 2 Housing cover 30 3 Case back 4 Stroke direction 5 Front side (hoist side) 6 Transverse direction 7 Front side (load side) 8th Display slot 9 Liquid crystal display 10 Metal frame 11 Shaft coupling 12 (hoist side) Shaft coupling (load side) 13 Suspension link 14 Load hook 15 Joint protrusion 16 Fixing projection 16' Mounting side 17 18" guide line 18." O-ring 19 Axial bearing 20 Inner tube 21 Intermediate cavity 22 cavity 23 Threaded bolt 24 Passage opening 25 16' inner tube face 26,&iacgr; 27.27' lead 28

31 Fixing screw

32 Bottom

33 strain gauges

34 Cable duct

35 Fixation

H-Il cutting line

4 April 1991

Claims (29)

5/13-90861
February 28, 1991 Expectations &bgr; 1. Load measuring and control devices that can be fixed in the lifting line of a hoist. 9 Display device (1) for measuring the effective force on the lifting line 10 towing capacity with a housing consisting of: 11 - running essentially in the lifting direction (5) of the lifting line 12 side walls (= 2.21) and
&eegr; - cover elements (= 3,4), &eegr; - which extend essentially transversely (= 7) to the stroke direction (5), is — which rest on the front sides (= 6,8;26,26') of the side walls (= 2,21) he and &igr;? — which together with the side walls (= 2.21) form a substantially which form closed hollow bodies, 19 characterized in that 20 a) a cover element (= 3.4) 21 aa) is formed as a membrane-like, flat body, 22 bb) acts as a connecting flange for adapting the lifting line and 23 cc) by the trailer load lifted by the lifting line elastically 24 is deformable 25 and 2β b) a film consisting essentially of a carrier film and a 27 Resistance element of existing strain gauges (33) 2β aa) is connected to the cover element (= 3,4) in terms of movement and 29 bb) whose resistance element is proportional to the elastic deformation of the μg of the cover element (= 3.4) while simultaneously changing its electrical si resistance is expandable such that sz cc) an electric brake proportional to the trailer load 33 resistance value is measurable. February 28, 1991 (&Igr;&Igr;:\&Agr;&Ngr;\908&bgr;1-5.&Tgr;&KHgr;&eegr; &igr; 2. Device (1) according to claim 1, a characterized by 3 that the side walls (= 2.21) are formed by a hollow cylinder whose 4 front sides (= 6.8:26.26') of disc-like, circular cover elements 5 (= 3.4) can be closed. 7 3. Device (1) according to claim 1 and claim 2, &bgr; characterized by &thgr; a division of the hollow cylinder into a cavity (23) of the hollow body to enclosing inner tube (21) and a housing outer wall forming, with the outer tube (2) surrounding the inner tube (21). 13 4. Device (1) according to one or more of the preceding claims, U characterized by is that the inner tube (21) and the outer tube (2) are spaced apart are arranged relative to each other so that between the inner tube outer wall and the &igr;? Outer tube inner wall an intermediate cavity (22) is formed. ig 5. Device (1) according to one or more of the preceding claims, µm characterized by 21 an air cushion placed in the intermediate cavity (22) for thermal insulation 22 of the cavity (23) enclosed by the inner tube (21). 24 6. Device (1) according to one or more of the preceding claims, 25 characterized by 2&bgr; that a cover element is designed as a housing cover (3) and that 27 Housing cover (3) facing away from the housing base (4) 2s forms. so 7. Device (1) according to one or more of the preceding claims, si characterized by &kgr; that the housing base (4) carries the strain gauge (33). 34 8. Device (1) according to one or more of the preceding claims, 35 characterized by se that the housing base (4) is made of high-tempered steel, 37 essentially circular disk and in the center of the disk a se shaft coupling (13) can be fixed. February 28, 1991 2 9. Device (1) according to one or more of the preceding claims, 3 characterized by 4 that the housing cover (3) is a substantially circular disc, in 5 at the centre of which a shaft coupling (12) can be fixed. 7 10. Device (1) according to claim 8 and claim 9, &bgr; characterized by 9 that in the shaft couplings (12,13) lifting devices (= 14,15) for 10 connection with the lifting line are adaptable in such a way that a 11 Housing cover (3) attached hoist side part and a 12 Housing bottom (4) hinged load-side part string with 13 suspended load measuring and display device (1) the 14 form lifting strand. ie 11. Device (1) according to one or more of the preceding claims, &igr;? characterized by te that the shaft couplings (12,13) and the lifting means (= 14,15) form a completely cardanic suspension for the load measuring and display device (1) 20 between the partial strands. 22 12. Device (1) according to one or more of the preceding claims, 23 characterized by 24 that the shaft couplings (12,13) have three finger-like in the stroke direction (5) 25 protruding, parallel, forming a joint socket 2β joint projections (16). 2β 13. Device (1) according to one or more of the preceding claims, 29 characterized by so that the stop means (= 14,15) complement the joint projections si have formed fixing projections (16 ¹ ) and in the manner of fingers 32 folded hands can be inserted into the joint projections (16). 34 14. Device (1) according to one or more of the preceding claims, 35 characterized by the joint projections (16) and the fixing projections (16') transversely (= 7) to the 37 Lifting direction (5) penetrating locking bolts such that shaft coupling se (12,13) and lifting means (= 14,15) form a hinge joint. February 28, 1991 2 15. Device (1) according to one or more of the preceding claims, 3 characterized by 4 inner tube faces flush with the cover elements (= 3,4) (26,26'). 7 16. Device (1) according to one or more of the preceding claims, &bgr; characterized by &thgr; that the housing cover (3) and the housing base (4) by means of the 10 Intermediate cavity (22) penetrated by threaded bolt (24) with flush 11 The inner tube (21) can be clamped against each other. 13 17. Device (1) according to one or more of the preceding claims, u characterized by is in the final assembly position facing each other, in the intermediate cavity (22) the protruding, step-like projections (27,27') on the housing cover (3) and &igr;? on the housing base (4) for fixing the inner tube (21) and the the outer tube (2) transverse (= 7) to the stroke direction (5). 20 18. Device (1) according to one or more of the preceding claims, 21 characterized by 22 that the outer tube (2) is supported radially by the projections (27,27") in the manner 23 of an axial floating bearing with clearance between the housing cover (3) and 24 Housing base (4). 2β 19. Device (1) according to one or more of the preceding claims, 27 characterized by 28 that the cavity (23) contains a measuring and display electronics 29 Encapsulates the printed circuit board (29,29") in such a way that the printed circuit board (29,29") &mgr; is mounted on stud bolts (30) connected to the housing base (4). 32 20. Device (1) according to one or more of the preceding claims, 33 characterized by 34 a permanently fixable to the outer tube (2), preferably 35 rectangular display slot (9) for accommodating a measured value display 3β (=10). February 28 1&THgr;&THgr;1 &igr; 21. Device (1) according to claim 20, 2 characterized by a digital liquid crystal display (10) for displaying the measured value and 4 a frame projecting in front of the liquid crystal display (10), 5 preferably metal frame (11), as a protective cover. &bgr; 7 22. Device (1) according to one or more of the preceding claims, &bgr; characterized by 9 that the strain gauge (33) has four ring-shaped, on a carrier foil &iacgr;&ogr; has vapor-deposited wires as a resistance element. 12 23. Device (1) according to claim 22, 13 characterized by 14 that the housing base (3) and the strain gauge (33) form a ring force sensor. 17 24. Device (1) according to one or more of the preceding claims, ie characterized by 19 that the strain gauge (33) as a strain gauge rosette 20 is trained. February 28, 19&THgr;1